A novel trinuclear zinc(II) cluster with a tetra­hedral ZnO₄ core

The reaction of 0.67 molar equivalents of the O,N,O′-tri­dentate zwitterionic Schiff base (2Z,4E)-4-[(2-hydroxy­phenyl)iminio]pent-2-en-2-olate (H₂L) with one equivalent of zinc(II) acetate in methanol affords a novel trinuclear Zn^II cluster, di-μ-acetato-1:2κ²O:O′;2:3κ²O:O′-dimethanol-1κO,3κO-bis­{μ-2-[(2E,3Z)-4-oxidopent-3-en-2-yl­ideneamino]phenol­ato}-1:2κ⁴O²,N,O⁴:O⁴;2:3κ⁴O⁴:O²,N,O⁴-trizinc(II), [Zn₃(C₁₁H₁₁NO₂)₂(C₂H₃O₂)₂(CH₄O)₂], (I), in which two bridging acetate ligands link the terminal square-based pyramidal Zn^II ions to the approximately tetra­hedral Zn^II ion at the core of the cluster. The ZnO₄ coordination group of the central Zn^II ion is established by two bridging phenolate and two bridging acetate O atoms. The remaining four coordination sites of each terminal Zn^II ion are occupied by methanol and deprotonated H₂L. Furthermore, the Zn-bound methanol hydroxyl groups are involved in complementary hydrogen bonding with the Zn-bound enolate O atom of a neighbouring mol­ecule, about an inversion centre in each case. The structure of (I) is therefore best described as an extended one-dimensional hydrogen-bonded chain of trinuclear Zn^II clusters.

S1. Comment

Schiff base ligands with O,N,O donor-atom sets may be prepared from several synthons depending on what structural, electronic or steric properties are required. One straightforward strategy for preparing resonance-stabilized nonplanar tridentate O,N,O Schiff base ligands based on the structure of (I) involves the condensation of pentane-2,4-dione and 2-aminophenol. In this ligand, nonbonded interactions between the aryl ring and closest methyl group distort the system from planarity (Kabak et al., 1998), a potentially useful tool for modulating the electronic properties of coordination compounds. There are three reported X-ray structures of the parent ligand system based on 2-aminophenol (Kabak et al., 1998; Chen et al., 1999; Rajnikant et al., 2006). Although there is some debate about the exact structure or resonance form of the ligand, it is best understood as a resonance hybrid with significant zwitterion character, as depicted in the scheme.

Coordination of (I), H₂L, to a metal ion requires the loss of two H atoms to form the tridentate dianion 2-[(2E,3Z)-4-oxidopent-3-en-2-ylideneamino]phenolate, L. Examples of structurally characterized complexes of L include the centrosymmetric tetranuclear Cu^II cluster Cu₄L₄ (Barclay & Hoskins, 1965), the dinuclear organometallic complex Ga₂(Me)₂L₂ (Shen et al., 2004), the unusual square-pyramidal Si^IV complexes Si(NCO)₂L₂ and Si(NCS)₂L₂ (Seiler et al., 2005), a six-coordinate Si^IV complex, SiL₂ (Seiler et al., 2005), a centrosymmetric dinuclear Cu^II cluster, Cu₂L₂ (utilizing the p-chloro analogue of L; Tahir et al., 1996), and the mixed-ligand complexes SiLX, where X is the dianion of 2-hydroxybenzoic acid, (S)-lactic acid, or 2-hydroxyethanoic acid (Seiler et al., 2007). While these examples illustrate some of the coordination chemistry possible with (I), further development and application of this type of ligand in both coordination and supramolecular chemistry are warranted.

Reaction of (I) with Zn^II in a 1:1 ratio in methanol should, in principle, generate the mononuclear Zn^II complexes ZnL(OHCH₃) or ZnL(OHCH₃)₂, due to the preference of Zn^II for a four- or five-coordinate geometry, respectively. In this paper we describe the isolation and structure elucidation of the title novel trinuclear Zn^II cluster, (II), generated from this reaction system when Zn^II acetate is used for metallation. Since only a few colourless crystals of (II) were located in the bulk pale-yellow polycrystalline product, we surmise that (II) is a stable yet minor component of the product mixture resulting from a 2:3 ligand–metal reaction stoichiometry.

The structure of (II) has a central ZnO₄ group with approximate tetrahedral (td) geometry forming the core of a trinuclear Zn^II cluster (Fig. 1). The central Zn^II ion is linked via bridging ligands (two acetate ions and two phenoxide O atoms) to two terminal Zn^II ions with square-pyramidal (spy) coordination. The five-coordinate geometry of each terminal Zn^II ion is brought about by ligation of the metal by a solvent-derived methanol molecule as the fifth ligand. The trinuclear cluster has approximate C₂ symmetry by virtue of a pseudo-twofold rotation axis passing through the central ZnO₄ core. The Zn(spy)—N and Zn(spy)—O(enolate) bonds average 2.054 (1) and 1.982 (14) Å, respectively. The Zn—O bonds involving the bridging phenoxide and acetate O atoms are short to the central Zn^II ion and longer to the terminal Zn^II ions, consistent with the geometrical constraints imposed by each tridentate Schiff base chelate in (II). More specifically, the Zn(spy)—O(phenoxide) bonds average 2.050 (5) Å within the five-membered chelate ring and 1.947 (6) Å outside the chelate ring to the central Zn^II ion. The Zn(spy)—O(acetate) and Zn(td)—O(acetate) bonds are also distinct, averaging 2.032 (11) and 1.938 (2) Å, respectively. Collectively, the ZnO₄ coordination group at the centre of the trinuclear cluster exhibits a mean Zn(td)—O distance of 1.942 (7) Å. The bonds to the axial methanol solvent molecules, Zn(spy)—O(methanol), average a fairly typical 2.021 (8) Å (Orpen et al., 1989).

Structurally characterized trinuclear Zn^II clusters stabilized by bridging acetate ligands are well known in the literature. In most cases, anionic O-donors surround the central Zn^II ion to give a six-coordinate nominally octahedral ZnO₆ coordination group, as is the case when two tridentate pyridineimineenolate ligands (de Hoog et al., 2004; Majumder et al., 2006) or two tridentate phenolateiminephenolate ligands (Gembicky et al., 2000) serve as the capping groups for the cluster. Interestingly, even tetradentate salen-type ligands, when metallated with Zn^II acetate, form trinuclear µ₂-acetate-bridged clusters with square-pyramidal terminal Zn^II ions and a central ZnO₆ core (Ülkü et al., 2001). Trinuclear Zn^II cluster formation is evidently favoured in the presence of acetate ions. What distinguishes compound (II) from previously described trinuclear Zn^II clusters is the fact that it is the first compound to be based upon a nominally tetrahedral ZnO₄ core.

Returning to the structure of (II), it is worth noting that the tridentate imineenolate ligands are nonplanar by virtue of the steric repulsion between the adjacent phenyl and methyl groups in the structure. The dihedral angles between the phenyl rings and imineenolate moieties in each ligand are 32.3 (3) and 28.3 (3)° for the ligands containing atoms N1 and N2, respectively. This dihedral angle is 32.9 (3)° in the free ligand (Kabak et al., 1998), suggesting that complexation of Zn^II does not lead to any measurable distortion of the tridentate chelate. The terminal square-pyramidal Zn^II ions Zn1 and Zn2 are displaced towards their axial methanol ligands from the four-atom mean planes passing through their equatorial ligand donor-atom sets by 0.423 (1) and 0.409 (1) Å, respectively. Furthermore, the angle between these latter two planes is 86.6 (3)°. The approximately orthogonal relative orientation of these two coordination group planes is a geometric manifestation of having two cis O-donor atoms in each plane as bridging groups, and thus cis ligands, to the central tetrahedral ZnO₄ core of the cluster.

Finally, the unit cell for (II) comprises two trinuclear clusters in general positions (Fig. 2). More interesting, however, is the fact that each molecule is a member of an extended one-dimensional hydrogen-bonded chain enabled by complementary hydrogen-bond formation between Zn-bound methanol molecules belonging to neighbouring trinuclear clusters in the crystalline solid state (Table 2, Fig. 3). Each trinuclear cluster is therefore related to its immediate neighbour in the chain by an inversion centre. The metal-bound solvent molecules evidently direct the extended structure of (II) in the crystal structure. One other trinuclear Zn^II cluster has been described with hydrogen bonding between metal-bound methanol molecules and neighbouring clusters and, consequently, extended chain formation in the crystalline solid state (Akine et al., 2007). The elegance and simplicity of the complementary hydrogen-bonding interactions displayed by (II) are, however, currently unmatched, at least for trinuclear clusters of the type presented here.

S2. Experimental

Compound (I) was prepared essentially as described in the literature (Kabak et al., 1998). Zinc acetate (1.000 g, 4.6 mmol) and (I) (0.871 g, 4.6 mmol) were weighed into a round-bottomed flask and dissolved in a minimum of methanol. The solution went bright yellow as it came to reflux. Triethylamine (0.920 g, 9.2 mmol) was added and the solution was left to reflux for 2 h. A yellow precipitate was filtered off and allowed to air dry. A crystal of (II) suitable for X-ray diffraction was grown by slow evaporation of the methanol solution. This crystal was a large colourless rectangular block amidst the bulk polycrystalline material (pale yellow).

S3. Refinement

The H atoms attached to methanol atoms O9 and O10 were located by difference Fourier synthesis and refined isotropically, with an O—H distance constraint of 0.82 (2) Å. The remaining H atoms were positioned geometrically and refined using a riding model, with C—H = 0.98 Å and U_iso(H) = 1.2U_eq(C) for methine H atoms, C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C) for aromatic H atoms, and C—H = 0.98 Å and U_iso(H) = 1.2U_eq(C) for methyl-group H atoms. For methyl H atoms, the torsion angle was optimized to fit the electron density.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: WinGX (Farrugia, 1999) and OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. The molecular structure of (II), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. Ball-and-tube representation of part of the unit-cell contents of (II). All H atoms, except those involved in hydrogen bonding (dashed lines), have been omitted for clarity. Linkage of the trinuclear Zn^II clusters to form an extended one-dimensional hydrogen-bonded chain is depicted for the lower molecule in the unit cell.
	Fig. 3. Partly labelled illustration of the inorganic core of three hydrogen-bonded molecules of (II). Displacement ellipsoids are drawn at the 40% probability level. H and C atoms have been omitted for clarity. Ct1 and Ct2 are the inversion centres, with coordinates [0,0,1/2] and [0,1/2,0], respectively. O atoms involved in complementary hydrogen bonding are linked by dashed bonds. [Symmetry codes: (i) -x, -y, -z + 1; (ii) -x, -y + 1, -z.]

di-µ-acetato-1:2κ²O:O';2:3κ²O:O'- dimethanol-1κO,2κO-bis{µ-2-[(2E,3Z)-4-oxidopent- 3-en-2-ylideneamino]phenolato}-1:2κ⁴O²,N, O⁴:O⁴;2:3κ⁴O⁴:O²,N, O⁴-trizinc(II)

Crystal data

[Zn3(C11H11NO2)2(C2H3O2)2(CH4O)2]	Z = 2
Mr = 756.70	F(000) = 776
Triclinic, P1	Dx = 1.579 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 10.5348 (2) Å	Cell parameters from 9497 reflections
b = 11.6175 (3) Å	θ = 3.7–27.0°
c = 13.5918 (4) Å	µ = 2.30 mm^−1
α = 88.768 (2)°	T = 295 K
β = 79.582 (2)°	Rhomb, colourless
γ = 76.594 (2)°	0.50 × 0.40 × 0.30 mm
V = 1591.11 (7) Å^3

Data collection

Oxford Diffraction Xcalibur2 CCD diffractometer	6772 independent reflections
Radiation source: Enhance (Mo) X-ray Source	4756 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
Detector resolution: 8.4190 pixels mm^-1	θmax = 27.0°, θmin = 3.7°
ω scans	h = −13→13
Absorption correction: multi-scan [CrysAlis RED (Oxford Diffraction, 2008). Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm]	k = −14→14
Tmin = 0.372, Tmax = 0.500	l = −17→17
17802 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.096	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0462P)^2 + 0.9978P] where P = (Fo^2 + 2Fc^2)/3
6772 reflections	(Δ/σ)max < 0.001
404 parameters	Δρmax = 0.47 e Å^−3
2 restraints	Δρmin = −0.43 e Å^−3

Special details

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Zn1	0.21151 (3)	0.03291 (3)	0.42509 (3)	0.0390 (1)
Zn2	0.18756 (4)	0.45343 (3)	0.07005 (3)	0.0388 (1)
Zn3	0.18967 (4)	0.23591 (3)	0.24102 (3)	0.0436 (1)
O1	0.3045 (2)	0.11101 (19)	0.30275 (16)	0.0415 (7)
O2	0.1692 (2)	−0.0245 (2)	0.56357 (16)	0.0488 (8)
O3	0.2720 (2)	0.36087 (18)	0.18079 (15)	0.0410 (7)
O4	0.1953 (2)	0.4970 (2)	−0.07159 (16)	0.0491 (8)
O5	0.0874 (3)	0.1897 (2)	0.47355 (18)	0.0613 (9)
O6	0.0429 (3)	0.3043 (3)	0.3463 (2)	0.0739 (10)
O7	0.1211 (3)	0.3125 (2)	0.03069 (19)	0.0649 (10)
O8	0.1137 (3)	0.1730 (2)	0.1403 (2)	0.0722 (11)
O9	0.0846 (3)	−0.0267 (3)	0.3560 (2)	0.0579 (9)
O10	0.0069 (3)	0.5377 (3)	0.14555 (19)	0.0593 (10)
N1	0.3968 (2)	−0.0789 (2)	0.40118 (18)	0.0359 (8)
N2	0.3098 (2)	0.5598 (2)	0.09533 (19)	0.0389 (8)
C1	0.4122 (3)	0.0348 (3)	0.2531 (2)	0.0385 (10)
C2	0.4734 (4)	0.0545 (3)	0.1568 (2)	0.0511 (11)
C3	0.5804 (4)	−0.0284 (4)	0.1082 (3)	0.0621 (14)
C4	0.6266 (4)	−0.1336 (4)	0.1527 (3)	0.0568 (14)
C5	0.5686 (3)	−0.1537 (3)	0.2486 (3)	0.0501 (12)
C6	0.4654 (3)	−0.0696 (3)	0.3020 (2)	0.0375 (10)
C7	0.6032 (3)	−0.1827 (3)	0.4604 (3)	0.0489 (11)
C8	0.4553 (3)	−0.1299 (3)	0.4741 (2)	0.0389 (10)
C9	0.3846 (3)	−0.1344 (3)	0.5732 (2)	0.0445 (11)
C10	0.2563 (3)	−0.0844 (3)	0.6132 (2)	0.0432 (11)
C11	0.2071 (4)	−0.0933 (4)	0.7235 (3)	0.0642 (16)
C12	0.3210 (3)	0.4322 (3)	0.2339 (2)	0.0391 (10)
C13	0.3511 (3)	0.4015 (3)	0.3282 (3)	0.0486 (12)
C14	0.3959 (4)	0.4762 (4)	0.3830 (3)	0.0577 (14)
C15	0.4100 (4)	0.5846 (4)	0.3455 (3)	0.0571 (12)
C16	0.3819 (3)	0.6166 (3)	0.2511 (3)	0.0486 (11)
C17	0.3420 (3)	0.5395 (3)	0.1924 (2)	0.0379 (10)
C18	0.4711 (4)	0.6848 (3)	0.0418 (3)	0.0550 (12)
C19	0.3670 (3)	0.6207 (3)	0.0255 (2)	0.0410 (10)
C20	0.3375 (3)	0.6275 (3)	−0.0737 (3)	0.0482 (11)
C21	0.2626 (3)	0.5700 (3)	−0.1171 (2)	0.0460 (11)
C22	0.2561 (4)	0.5841 (4)	−0.2257 (3)	0.0616 (14)
C23	0.0202 (4)	0.2750 (3)	0.4346 (3)	0.0573 (12)
C24	−0.1017 (6)	0.3475 (6)	0.4992 (4)	0.132 (3)
C25	0.0883 (3)	0.2227 (3)	0.0620 (2)	0.0436 (11)
C26	0.0129 (5)	0.1654 (4)	0.0015 (3)	0.0696 (16)
C27	0.1182 (5)	−0.1028 (4)	0.2725 (4)	0.0862 (19)
C28	−0.0246 (5)	0.6086 (4)	0.2313 (3)	0.0822 (19)
H2	0.44170	0.12420	0.12510	0.0620*
H3	0.62200	−0.01320	0.04450	0.0740*
H4	0.69650	−0.19070	0.11810	0.0680*
H5	0.59940	−0.22520	0.27820	0.0600*
H7A	0.62160	−0.26380	0.43840	0.0730*
H7B	0.63250	−0.17870	0.52280	0.0730*
H7C	0.64910	−0.13900	0.41120	0.0730*
H9	0.43370	−0.17830	0.61740	0.0530*
H11A	0.18350	−0.01580	0.75420	0.0960*
H11B	0.27580	−0.14300	0.75320	0.0960*
H11C	0.13070	−0.12680	0.73340	0.0960*
H13	0.34050	0.32890	0.35430	0.0580*
H14	0.41670	0.45390	0.44530	0.0690*
H15	0.43820	0.63630	0.38320	0.0680*
H16	0.38980	0.69060	0.22690	0.0580*
H18A	0.42870	0.76000	0.07420	0.0820*
H18B	0.52320	0.69680	−0.02150	0.0820*
H18C	0.52770	0.63820	0.08310	0.0820*
H20	0.37590	0.67970	−0.11500	0.0580*
H22A	0.28390	0.50780	−0.25870	0.0930*
H22B	0.31370	0.63360	−0.25500	0.0930*
H22C	0.16670	0.61980	−0.23310	0.0930*
H24A	−0.07620	0.39290	0.54720	0.1980*
H24B	−0.15350	0.29590	0.53350	0.1980*
H24C	−0.15350	0.39990	0.45810	0.1980*
H26A	−0.04000	0.22490	−0.03370	0.1040*
H26B	−0.04380	0.12480	0.04530	0.1040*
H26C	0.07420	0.10970	−0.04570	0.1040*
H27A	0.10910	−0.05740	0.21320	0.1290*
H27B	0.06020	−0.15640	0.27930	0.1290*
H27C	0.20830	−0.14710	0.26730	0.1290*
H28A	−0.05960	0.56610	0.28710	0.1230*
H28B	−0.08990	0.67890	0.22220	0.1230*
H28C	0.05370	0.63000	0.24410	0.1230*
H100	0.007 (2)	−0.009 (4)	0.382 (3)	0.098 (18)*
H200	−0.061 (3)	0.530 (4)	0.128 (3)	0.071 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0340 (2)	0.0464 (2)	0.0379 (2)	−0.0101 (2)	−0.0104 (2)	0.0143 (2)
Zn2	0.0398 (2)	0.0425 (2)	0.0393 (2)	−0.0165 (2)	−0.0134 (2)	0.0130 (2)
Zn3	0.0421 (2)	0.0467 (2)	0.0457 (2)	−0.0158 (2)	−0.0132 (2)	0.0212 (2)
O1	0.0385 (12)	0.0424 (12)	0.0418 (12)	−0.0070 (10)	−0.0070 (10)	0.0148 (10)
O2	0.0365 (13)	0.0682 (15)	0.0412 (12)	−0.0099 (11)	−0.0106 (10)	0.0207 (11)
O3	0.0511 (14)	0.0403 (12)	0.0399 (12)	−0.0207 (10)	−0.0187 (10)	0.0177 (9)
O4	0.0461 (14)	0.0689 (15)	0.0420 (13)	−0.0285 (12)	−0.0156 (10)	0.0194 (11)
O5	0.0641 (17)	0.0580 (16)	0.0498 (15)	0.0042 (13)	−0.0041 (13)	0.0098 (12)
O6	0.0540 (17)	0.088 (2)	0.0617 (17)	0.0094 (15)	−0.0005 (13)	0.0309 (15)
O7	0.101 (2)	0.0525 (15)	0.0600 (16)	−0.0395 (16)	−0.0367 (15)	0.0154 (13)
O8	0.099 (2)	0.0753 (19)	0.0696 (18)	−0.0539 (17)	−0.0465 (17)	0.0351 (15)
O9	0.0388 (15)	0.0861 (19)	0.0529 (15)	−0.0204 (14)	−0.0104 (12)	−0.0086 (14)
O10	0.0382 (15)	0.091 (2)	0.0512 (15)	−0.0168 (14)	−0.0108 (11)	−0.0133 (14)
N1	0.0350 (14)	0.0341 (13)	0.0419 (14)	−0.0102 (11)	−0.0136 (11)	0.0088 (11)
N2	0.0353 (14)	0.0404 (14)	0.0454 (15)	−0.0139 (12)	−0.0138 (11)	0.0133 (12)
C1	0.0330 (16)	0.0481 (18)	0.0387 (17)	−0.0153 (14)	−0.0108 (13)	0.0062 (14)
C2	0.048 (2)	0.066 (2)	0.0421 (19)	−0.0169 (18)	−0.0122 (16)	0.0137 (17)
C3	0.051 (2)	0.098 (3)	0.0384 (19)	−0.022 (2)	−0.0046 (17)	0.000 (2)
C4	0.044 (2)	0.072 (3)	0.052 (2)	−0.0090 (19)	−0.0063 (17)	−0.016 (2)
C5	0.043 (2)	0.050 (2)	0.059 (2)	−0.0096 (16)	−0.0147 (16)	−0.0036 (17)
C6	0.0324 (16)	0.0432 (17)	0.0415 (17)	−0.0138 (14)	−0.0126 (13)	0.0021 (14)
C7	0.0420 (19)	0.0474 (19)	0.062 (2)	−0.0111 (16)	−0.0223 (16)	0.0117 (17)
C8	0.0388 (17)	0.0348 (16)	0.0489 (18)	−0.0134 (14)	−0.0177 (14)	0.0100 (14)
C9	0.047 (2)	0.0442 (18)	0.0485 (19)	−0.0127 (15)	−0.0244 (16)	0.0209 (15)
C10	0.049 (2)	0.0448 (18)	0.0431 (18)	−0.0197 (16)	−0.0176 (15)	0.0173 (15)
C11	0.062 (3)	0.084 (3)	0.045 (2)	−0.011 (2)	−0.0154 (18)	0.021 (2)
C12	0.0346 (17)	0.0430 (18)	0.0416 (17)	−0.0114 (14)	−0.0095 (13)	0.0053 (14)
C13	0.052 (2)	0.051 (2)	0.049 (2)	−0.0172 (17)	−0.0199 (16)	0.0150 (16)
C14	0.062 (2)	0.073 (3)	0.046 (2)	−0.022 (2)	−0.0226 (18)	0.0063 (19)
C15	0.057 (2)	0.067 (2)	0.056 (2)	−0.026 (2)	−0.0165 (18)	−0.0076 (19)
C16	0.0439 (19)	0.0454 (19)	0.059 (2)	−0.0154 (16)	−0.0095 (16)	0.0012 (16)
C17	0.0279 (15)	0.0400 (17)	0.0454 (18)	−0.0058 (13)	−0.0089 (13)	0.0047 (14)
C18	0.054 (2)	0.052 (2)	0.067 (2)	−0.0280 (18)	−0.0133 (18)	0.0156 (18)
C19	0.0341 (17)	0.0361 (16)	0.052 (2)	−0.0081 (13)	−0.0067 (14)	0.0087 (14)
C20	0.0427 (19)	0.0466 (19)	0.056 (2)	−0.0131 (16)	−0.0097 (16)	0.0255 (16)
C21	0.0328 (17)	0.055 (2)	0.0465 (19)	−0.0041 (15)	−0.0078 (14)	0.0189 (16)
C22	0.059 (2)	0.081 (3)	0.049 (2)	−0.025 (2)	−0.0123 (18)	0.024 (2)
C23	0.049 (2)	0.061 (2)	0.055 (2)	−0.0027 (19)	−0.0054 (18)	0.0098 (19)
C24	0.122 (5)	0.131 (5)	0.080 (4)	0.063 (4)	0.022 (3)	0.026 (3)
C25	0.0426 (19)	0.0450 (19)	0.0435 (19)	−0.0111 (15)	−0.0074 (15)	−0.0003 (15)
C26	0.094 (3)	0.062 (2)	0.068 (3)	−0.036 (2)	−0.031 (2)	0.000 (2)
C27	0.069 (3)	0.077 (3)	0.114 (4)	−0.013 (2)	−0.022 (3)	−0.028 (3)
C28	0.066 (3)	0.100 (4)	0.080 (3)	−0.016 (3)	−0.012 (2)	−0.032 (3)

Geometric parameters (Å, º)

Zn1—O1	2.075 (2)	C14—C15	1.378 (6)
Zn1—O2	1.992 (2)	C15—C16	1.392 (6)
Zn1—O5	2.024 (2)	C16—C17	1.394 (5)
Zn1—O9	2.015 (3)	C18—C19	1.510 (5)
Zn1—N1	2.053 (2)	C19—C20	1.434 (5)
Zn2—O3	2.046 (2)	C20—C21	1.359 (5)
Zn2—O4	1.972 (2)	C21—C22	1.494 (5)
Zn2—O7	2.040 (3)	C23—C24	1.501 (7)
Zn2—O10	2.027 (3)	C25—C26	1.502 (6)
Zn2—N2	2.054 (2)	C2—H2	0.9300
Zn3—O1	1.943 (2)	C3—H3	0.9300
Zn3—O3	1.951 (2)	C4—H4	0.9300
Zn3—O6	1.936 (3)	C5—H5	0.9300
Zn3—O8	1.939 (3)	C7—H7A	0.9600
O1—C1	1.345 (4)	C7—H7B	0.9600
O2—C10	1.300 (4)	C7—H7C	0.9600
O3—C12	1.354 (4)	C9—H9	0.9300
O4—C21	1.305 (4)	C11—H11A	0.9600
O5—C23	1.246 (4)	C11—H11B	0.9600
O6—C23	1.237 (5)	C11—H11C	0.9600
O7—C25	1.218 (4)	C13—H13	0.9300
O8—C25	1.242 (4)	C14—H14	0.9300
O9—C27	1.396 (6)	C15—H15	0.9300
O10—C28	1.386 (5)	C16—H16	0.9300
O9—H100	0.81 (3)	C18—H18A	0.9600
O10—H200	0.82 (3)	C18—H18B	0.9600
N1—C6	1.424 (4)	C18—H18C	0.9600
N1—C8	1.319 (4)	C20—H20	0.9300
N2—C19	1.314 (4)	C22—H22A	0.9600
N2—C17	1.422 (4)	C22—H22B	0.9600
C1—C6	1.418 (5)	C22—H22C	0.9600
C1—C2	1.390 (4)	C24—H24A	0.9600
C2—C3	1.375 (6)	C24—H24B	0.9600
C3—C4	1.377 (6)	C24—H24C	0.9600
C4—C5	1.376 (6)	C26—H26A	0.9600
C5—C6	1.384 (5)	C26—H26B	0.9600
C7—C8	1.515 (5)	C26—H26C	0.9600
C8—C9	1.423 (4)	C27—H27A	0.9600
C9—C10	1.358 (5)	C27—H27B	0.9600
C10—C11	1.505 (5)	C27—H27C	0.9600
C12—C17	1.405 (5)	C28—H28A	0.9600
C12—C13	1.395 (5)	C28—H28B	0.9600
C13—C14	1.370 (6)	C28—H28C	0.9600
O1—Zn1—O2	160.21 (9)	N2—C19—C20	121.8 (3)
O1—Zn1—O5	91.74 (9)	C19—C20—C21	130.5 (3)
O1—Zn1—O9	97.88 (10)	O4—C21—C20	124.9 (3)
O1—Zn1—N1	79.38 (9)	O4—C21—C22	114.4 (3)
O2—Zn1—O5	87.33 (9)	C20—C21—C22	120.6 (3)
O2—Zn1—O9	101.87 (10)	O5—C23—O6	125.9 (4)
O2—Zn1—N1	91.97 (9)	O5—C23—C24	117.6 (4)
O5—Zn1—O9	96.62 (13)	O6—C23—C24	116.5 (4)
O5—Zn1—N1	151.03 (11)	O7—C25—C26	118.3 (3)
O9—Zn1—N1	111.82 (11)	O8—C25—C26	116.6 (3)
O3—Zn2—O4	150.52 (9)	O7—C25—O8	125.1 (3)
O3—Zn2—O7	92.03 (9)	C1—C2—H2	120.00
O3—Zn2—O10	102.11 (10)	C3—C2—H2	120.00
O3—Zn2—N2	80.33 (9)	C2—C3—H3	120.00
O4—Zn2—O7	85.31 (10)	C4—C3—H3	120.00
O4—Zn2—O10	107.35 (10)	C3—C4—H4	120.00
O4—Zn2—N2	93.50 (10)	C5—C4—H4	120.00
O7—Zn2—O10	93.45 (13)	C4—C5—H5	119.00
O7—Zn2—N2	162.31 (11)	C6—C5—H5	119.00
O10—Zn2—N2	103.71 (11)	C8—C7—H7A	109.00
O1—Zn3—O3	115.38 (9)	C8—C7—H7B	109.00
O1—Zn3—O6	105.92 (11)	C8—C7—H7C	109.00
O1—Zn3—O8	111.55 (10)	H7A—C7—H7B	110.00
O3—Zn3—O6	109.10 (12)	H7A—C7—H7C	109.00
O3—Zn3—O8	108.13 (10)	H7B—C7—H7C	110.00
O6—Zn3—O8	106.37 (13)	C8—C9—H9	115.00
Zn1—O1—Zn3	115.71 (11)	C10—C9—H9	115.00
Zn1—O1—C1	111.56 (18)	C10—C11—H11A	109.00
Zn3—O1—C1	124.78 (18)	C10—C11—H11B	109.00
Zn1—O2—C10	124.74 (19)	C10—C11—H11C	109.00
Zn2—O3—Zn3	116.30 (11)	H11A—C11—H11B	110.00
Zn2—O3—C12	110.36 (18)	H11A—C11—H11C	109.00
Zn3—O3—C12	123.17 (18)	H11B—C11—H11C	109.00
Zn2—O4—C21	125.10 (19)	C12—C13—H13	119.00
Zn1—O5—C23	136.1 (2)	C14—C13—H13	119.00
Zn3—O6—C23	129.0 (3)	C13—C14—H14	120.00
Zn2—O7—C25	143.6 (2)	C15—C14—H14	120.00
Zn3—O8—C25	125.8 (2)	C14—C15—H15	120.00
Zn1—O9—C27	126.5 (3)	C16—C15—H15	120.00
Zn2—O10—C28	129.2 (3)	C15—C16—H16	119.00
Zn1—O9—H100	117 (3)	C17—C16—H16	120.00
C27—O9—H100	117 (3)	C19—C18—H18A	110.00
Zn2—O10—H200	121 (3)	C19—C18—H18B	110.00
C28—O10—H200	110 (3)	C19—C18—H18C	109.00
C6—N1—C8	123.6 (2)	H18A—C18—H18B	109.00
Zn1—N1—C6	111.21 (19)	H18A—C18—H18C	110.00
Zn1—N1—C8	123.3 (2)	H18B—C18—H18C	109.00
Zn2—N2—C19	123.9 (2)	C19—C20—H20	115.00
C17—N2—C19	125.4 (3)	C21—C20—H20	115.00
Zn2—N2—C17	109.75 (19)	C21—C22—H22A	109.00
O1—C1—C2	122.9 (3)	C21—C22—H22B	109.00
O1—C1—C6	118.2 (2)	C21—C22—H22C	109.00
C2—C1—C6	119.0 (3)	H22A—C22—H22B	109.00
C1—C2—C3	120.4 (3)	H22A—C22—H22C	110.00
C2—C3—C4	120.8 (4)	H22B—C22—H22C	110.00
C3—C4—C5	119.6 (4)	C23—C24—H24A	109.00
C4—C5—C6	121.3 (3)	C23—C24—H24B	109.00
N1—C6—C1	114.1 (3)	C23—C24—H24C	109.00
N1—C6—C5	127.1 (3)	H24A—C24—H24B	110.00
C1—C6—C5	118.7 (3)	H24A—C24—H24C	110.00
C7—C8—C9	114.8 (3)	H24B—C24—H24C	109.00
N1—C8—C9	122.2 (3)	C25—C26—H26A	109.00
N1—C8—C7	122.9 (3)	C25—C26—H26B	109.00
C8—C9—C10	129.9 (3)	C25—C26—H26C	110.00
O2—C10—C11	115.2 (3)	H26A—C26—H26B	109.00
C9—C10—C11	119.9 (3)	H26A—C26—H26C	109.00
O2—C10—C9	124.9 (3)	H26B—C26—H26C	109.00
O3—C12—C13	121.6 (3)	O9—C27—H27A	110.00
O3—C12—C17	118.8 (2)	O9—C27—H27B	110.00
C13—C12—C17	119.6 (3)	O9—C27—H27C	110.00
C12—C13—C14	121.2 (3)	H27A—C27—H27B	109.00
C13—C14—C15	119.8 (4)	H27A—C27—H27C	109.00
C14—C15—C16	120.0 (4)	H27B—C27—H27C	109.00
C15—C16—C17	121.0 (3)	O10—C28—H28A	110.00
N2—C17—C12	114.3 (3)	O10—C28—H28B	109.00
N2—C17—C16	127.3 (3)	O10—C28—H28C	110.00
C12—C17—C16	118.3 (3)	H28A—C28—H28B	109.00
C18—C19—C20	115.0 (3)	H28A—C28—H28C	109.00
N2—C19—C18	123.2 (3)	H28B—C28—H28C	109.00
O5—Zn1—O1—Zn3	−37.35 (13)	O1—Zn3—O6—C23	−2.3 (4)
O9—Zn1—O1—Zn3	59.58 (14)	Zn1—O1—C1—C2	164.3 (3)
N1—Zn1—O1—Zn3	170.42 (13)	Zn3—O1—C1—C2	16.9 (4)
O5—Zn1—O1—C1	172.1 (2)	Zn1—O1—C1—C6	−16.1 (3)
O9—Zn1—O1—C1	−91.0 (2)	Zn3—O1—C1—C6	−163.5 (2)
N1—Zn1—O1—C1	19.86 (19)	Zn1—O2—C10—C9	−12.1 (5)
N1—Zn1—O5—C23	114.8 (4)	Zn1—O2—C10—C11	166.1 (2)
N1—Zn1—O2—C10	16.0 (3)	Zn2—O3—C12—C13	162.6 (3)
O1—Zn1—N1—C6	−20.25 (19)	Zn3—O3—C12—C17	−161.4 (2)
O2—Zn1—N1—C6	177.7 (2)	Zn3—O3—C12—C13	18.7 (4)
O5—Zn1—N1—C6	−94.3 (3)	Zn2—O3—C12—C17	−17.6 (3)
O9—Zn1—N1—C6	74.1 (2)	Zn2—O4—C21—C22	177.7 (2)
O5—Zn1—O2—C10	−135.0 (3)	Zn2—O4—C21—C20	−0.2 (5)
O9—Zn1—O2—C10	128.8 (3)	Zn1—O5—C23—C24	153.2 (4)
O2—Zn1—N1—C8	−17.5 (2)	Zn1—O5—C23—O6	−25.0 (7)
O1—Zn1—O9—C27	57.4 (3)	Zn3—O6—C23—O5	−2.9 (6)
O2—Zn1—O9—C27	−121.3 (3)	Zn3—O6—C23—C24	178.8 (3)
O5—Zn1—O9—C27	150.1 (3)	Zn2—O7—C25—C26	164.7 (3)
N1—Zn1—O9—C27	−24.3 (4)	Zn2—O7—C25—O8	−16.3 (7)
O2—Zn1—O5—C23	−155.9 (4)	Zn3—O8—C25—C26	−172.0 (3)
O9—Zn1—O5—C23	−54.3 (4)	Zn3—O8—C25—O7	8.9 (5)
O1—Zn1—N1—C8	144.6 (2)	Zn1—N1—C8—C9	14.9 (4)
O5—Zn1—N1—C8	70.6 (3)	C8—N1—C6—C5	38.3 (5)
O9—Zn1—N1—C8	−121.1 (2)	C6—N1—C8—C7	1.0 (5)
O1—Zn1—O5—C23	43.8 (4)	Zn1—N1—C8—C7	−162.0 (2)
N2—Zn2—O3—C12	21.28 (19)	C6—N1—C8—C9	178.0 (3)
O4—Zn2—O7—C25	176.7 (4)	Zn1—N1—C6—C1	18.0 (3)
O3—Zn2—O7—C25	26.1 (4)	C8—N1—C6—C1	−146.8 (3)
O10—Zn2—O3—C12	−80.8 (2)	Zn1—N1—C6—C5	−156.9 (3)
O7—Zn2—O10—C28	145.6 (3)	Zn2—N2—C17—C12	18.8 (3)
N2—Zn2—O10—C28	−30.0 (4)	C19—N2—C17—C12	−150.0 (3)
O10—Zn2—O4—C21	105.8 (3)	Zn2—N2—C19—C20	6.6 (4)
N2—Zn2—O4—C21	0.3 (3)	C17—N2—C19—C20	173.9 (3)
O10—Zn2—O7—C25	−76.2 (4)	Zn2—N2—C19—C18	−171.2 (2)
O4—Zn2—O3—C12	101.2 (2)	C17—N2—C19—C18	−3.9 (5)
O7—Zn2—O3—C12	−174.8 (2)	C19—N2—C17—C16	34.8 (5)
O4—Zn2—O10—C28	−128.2 (3)	Zn2—N2—C17—C16	−156.4 (3)
O10—Zn2—N2—C19	−112.4 (2)	C2—C1—C6—C5	−6.2 (5)
O3—Zn2—O4—C21	−76.2 (3)	O1—C1—C6—C5	174.2 (3)
O4—Zn2—O3—Zn3	−112.29 (18)	C2—C1—C6—N1	178.4 (3)
O7—Zn2—O3—Zn3	−28.22 (13)	C6—C1—C2—C3	2.8 (5)
O10—Zn2—O3—Zn3	65.75 (14)	O1—C1—C6—N1	−1.2 (4)
N2—Zn2—O3—Zn3	167.83 (13)	O1—C1—C2—C3	−177.7 (3)
O3—Zn2—O10—C28	52.8 (4)	C1—C2—C3—C4	1.8 (6)
O4—Zn2—N2—C19	−3.6 (2)	C2—C3—C4—C5	−2.9 (6)
O3—Zn2—N2—C17	−21.62 (19)	C3—C4—C5—C6	−0.8 (6)
O4—Zn2—N2—C17	−172.59 (19)	C4—C5—C6—N1	180.0 (3)
O7—Zn2—O4—C21	−162.0 (3)	C4—C5—C6—C1	5.2 (5)
O3—Zn2—N2—C19	147.4 (3)	C7—C8—C9—C10	171.9 (3)
O10—Zn2—N2—C17	78.6 (2)	N1—C8—C9—C10	−5.3 (6)
O8—Zn3—O6—C23	116.5 (4)	C8—C9—C10—C11	−174.7 (4)
O8—Zn3—O1—Zn1	−87.47 (14)	C8—C9—C10—O2	3.4 (6)
O6—Zn3—O1—Zn1	27.85 (15)	C13—C12—C17—N2	178.9 (3)
O3—Zn3—O6—C23	−127.1 (4)	O3—C12—C17—C16	174.7 (3)
O3—Zn3—O1—C1	−65.2 (3)	O3—C12—C17—N2	−0.9 (4)
O6—Zn3—O1—C1	174.0 (2)	O3—C12—C13—C14	−177.5 (3)
O8—Zn3—O1—C1	58.7 (3)	C13—C12—C17—C16	−5.4 (5)
O1—Zn3—O8—C25	−146.3 (3)	C17—C12—C13—C14	2.6 (5)
O3—Zn3—O8—C25	−18.4 (3)	C12—C13—C14—C15	0.9 (6)
O8—Zn3—O3—C12	172.3 (2)	C13—C14—C15—C16	−1.6 (6)
O6—Zn3—O8—C25	98.7 (3)	C14—C15—C16—C17	−1.3 (6)
O1—Zn3—O3—Zn2	156.06 (10)	C15—C16—C17—C12	4.8 (5)
O6—Zn3—O3—Zn2	−84.89 (14)	C15—C16—C17—N2	179.8 (3)
O8—Zn3—O3—Zn2	30.39 (14)	N2—C19—C20—C21	−6.8 (6)
O1—Zn3—O3—C12	−62.1 (2)	C18—C19—C20—C21	171.2 (4)
O6—Zn3—O3—C12	57.0 (3)	C19—C20—C21—O4	3.2 (6)
O3—Zn3—O1—Zn1	148.63 (10)	C19—C20—C21—C22	−174.6 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O9—H100···O2^i	0.81 (2)	1.83 (2)	2.633 (2)	176 (1)
O10—H200···O4^ii	0.81 (2)	1.82 (2)	2.627 (2)	176 (1)

Symmetry codes: (i) −x, −y, −z+1; (ii) −x, −y+1, −z.